San Antonio is to small of a city in my opinion. Same as Portland and Salt Lake City. If MLB feels the need to move anywhere I suspect the only really viable candidates are Montreal or maybe...maybe...Vancouver.

Lip

A stadium on the Vegas Strip would be incredibly successful, I believe. I know MLB would never go for it due to the league's uneasy history with gambling, and I realize the local market in Vegas is relatively small, but attendance would be strong from visiting fans and just tourists who want a diversion. Pipe dream, but it would be awesome.

Otherwise, the only other market that really makes sense is Montreal. With a modern stadium and an ownership group that is committed to the market, the fans there will come out. Basing Montreal's viability on the Expos' last few years' attendance figures just isn't fair, as Loria and MLB did everything they could to sabotage that fanbase (and playing in easily the worst ballpark I've ever visited surely didn't help).